Published European patent document EP 0 828 075 describes a fuel injector for the direct injection of fuel into the combustion chamber of an internal combustion engine, which has a device for adjusting the temperature in the region of the valve tip so as to reduce deposits in this area. The device is embodied in the form of a coating made of a thermally conductive material on the valve tip.
Disadvantages of the fuel injector described in the European patent document EP 0 828 075 are the high demands regarding the accuracy of fit of the components and the complicated installation, which is involved and thus cost-intensive.
Furthermore, a fuel injector for the direct injection of fuel into the combustion chamber of a mixture-compressing internal combustion engine having external ignition is described in published German patent document DE 101 09 407. It includes a valve housing formed by a nozzle body, and a sealing ring which seals the fuel injector from a cylinder head of the internal combustion engine. The sealing ring has a convexly arched profile, the two ends of the sealing ring axially overlapping in the form of a step.
Particularly disadvantageous in the fuel injector described in published German patent document DE 101 09 407 is the air gap between the fuel injector and the cylinder head, which allows only limited heat transfer. This is disadvantageous in reducing deposits on the valve tip since the temperature in the region of the spray-discharge orifices must be as low as possible so as to avoid deposits.